istream_iterator 与 ostream_iterator 简单的用法

#include<fstream>
#include<iterator>
#include<string>
#include<vector>
#include<algorithm>

using namespace std;

int main()
{
 string from,to;
 
 cin>>from>>to;

 ifstream ifs(from.c_str());

 istream_iterator<string>ii(ifs);
 istream_iterator<string>eos;

 vector<string>v;

 copy(ii,eos,back_inserter(v));
 sort(v.begin(),v.end());
 copy(v.begin(), v.end(),ostream_iterator<string>(cout, " ") );

 ofstream ofs(to.c_str(),ios_base::app);
 ostream_iterator<string>oo(ofs);
 unique_copy(v.begin(),v.end(),*oo);

 ifs.close();
 ofs.close();
 
 system("pause");

 return 0;
}